Phoenix - Tea party supporters packed a Phoenix convention center Saturday to hear from two possible contenders for next year's Republican presidential nomination - an election the conservative populist movement is determined to shape after helping the GOP to big gains in the midterm elections.

Former Minnesota Gov. Tim Pawlenty aimed to impress more than 2,000 members of the Tea Party Patriots with a full-throated call to "take back our country." Texas Rep. Ron Paul, already embraced by tea party members, also spoke. The segment of engaged voters could prove vital to Republican White House hopefuls, but it's an audience that is skeptical of the politicians courting their backing.

"They're good speakers. They know what to say to inspire an audience. But I'm looking for substance I haven't found yet," said retiree Kaye Woodward of Livingston, Texas.

Potential candidates are trying to figure out how far they need to go to win over the tea party - and what spoils that would bring. Democrats are watching too, eager to portray President Barack Obama's eventual challenger as beholden to the political far right.

Pawlenty waved a copy of the U.S. Constitution after railing against "the royal triangle of greed: big government, big unions and big bailed-out businesses." The former governor also paid homage to a longshot New York gubernatorial candidate who ran last year using the slogan "the rent is too damn high."

"So here's our simple motto: 'The government's too damn big!'" Pawlenty said.

Paul, who ran for president in 2008 and is thinking of doing it again, urged tea party members at the conference to keep up the pressure for sweeping change.

"I wish I could say you were the majority, but we are still the minority," the Texas congressman said.

All of the Republicans considered likely to run for president have said they believe in the core tea party principles of limited government and fiscal restraint, and they play up their own efforts to stymie the agendas of Obama and the Congressional Democrats - most notably the federal health care overhaul that gave rise to the tea party movement.

But some Republicans would have a head start among tea partiers if they run. Former Alaska Gov. Sarah Palin and Minnesota Rep. Michele Bachmann - who built a tea party caucus in Congress - both enjoy star status in the movement for their plainspoken ways and adherence to the movement's core values.

Others, like Pawlenty, have had to do more to build their reputation. Pawlenty won plaudits for trying to stop the implementation of the health care overhaul in Minnesota, but he drew scorn from tea partiers for using billions of federal stimulus dollars to balance the state budget.

Former House Speaker Newt Gingrich forged bonds last fall by helping train local tea party activists through his American Solutions organization, but others view him as an insider and they can't get past his decision to back a moderate Republican candidate over a conservative in a closely watched New York congressional election.

Former Massachusetts Gov. Mitt Romney sent loads of money to tea party-backed candidates in 2010, but he is weighted down by a state law he helped engineer that expanded health coverage to the uninsured.

Former school principal Charles Wendler, a tea party member from of Las Cruces, N.M., said he's not enthusiastic about those likely candidates.

"We need to have somebody who is going to go "POOF' and appear and is going to take people by storm," Wendler said. "We need to have a grassroots candidate that doesn't have the baggage that these folks have."

It has yet to be determined how the tea party will influence the GOP primaries and the general election.

Tea Party Patriots co-founder Mark Meckler said candidates hoping for a tangible payoff from efforts to woo its members probably won't see one. Unlike interest groups that dangle endorsements, tea party members think they will wield more clout if their umbrella organization withholds any kind of official backing.

"Once the endorsement is made that politician owns the group. It doesn't matter anymore. You are now part of their literature. You are now part of their stump speech," Meckler said. "Even when a candidate goes sideways and does something a group might fundamentally disagree with, you just don't see withdrawn endorsements."

The tea party portrays itself as a leaderless web of activists, and this could complicate any collective display of might by splitting tea party support among several candidates.

In state after state, however, tea party activists are penetrating the Republican apparatus. Tea party figure Jack Kimball took over in January as Republican chairman in New Hampshire, which holds the first primary.

Veteran Republican strategist Saul Anuzis said the tea party's institutional presence alone makes it impossible for 2012 presidential candidates to ignore as they press ahead.

"The tea party is now a big part of the calculus of the Republican Party," said Anuzis, former chairman of the Michigan GOP. "It's not going to be the tea party necessarily as an entity, it's the fact that tea party activists are getting involved across the country in mainstream political movement taking over local parties and local leadership posts."

While the tea party provided fuel for the GOP's big electoral gains in November, Democrats see an upside if 2012 hopefuls battle for tea party backing ahead of an election where turnout will be larger and swing voters more critical.

"Establishment Republicans are afraid of losing to the far right in their primaries so they're playing to the far right," said Democratic political consultant Mo Elleithee, adding, "To the extent that the Republican candidates play to the extreme wing of their party, the better it is."

In a speech to conservatives this month, Mississippi Gov. Haley Barbour scoffed at suggestions the tea party causes problems for the GOP, deriding it as "a case of the left whistling past the graveyard."

"Americans motivated to participate in the tea party movement were upset by the very same policy issues of Republican volunteers and leaders," Barbour, who is considering a run, told the Conservative Political Action Conference.

Indiana Gov. Mitch Daniels, who hasn't ruled himself out the race, struck a more cautious note in a speech to the same group. Daniels warned that "purity in martyrdom is for suicide bombers" and said the worst outcome for his party in 2012 "would be to win the election and then prove ourselves incapable of turning the ship of state before it went on the rocks, with us at the helm."